1. Field of the Invention
The present invention relates to a seed boot attachment and wear resistant inserts therefor. More particularly, the seed boot attachment of the present invention includes cobalt and tungsten carbide inserts brazed to an austempered ductile iron or chrome casting to enhance wear life of the boot and to maintain the separation between the seed and the fertilizer and the depth of seed placement.
2. Description of the Related Art
The agricultural industry is employing larger and more efficient one-path planter systems for minimal tillage planting. The proper depositing of seeds and or seeds and fertilizer into a v-shaped furrow formed in the soil requires special care in handling the seeds and/or fertilizer and in maintaining the side walls of the furrow to ensure that the seed and/or fertilizer is/are deposited within the v-shaped furrow at the proper seed planting depths. If a seed boot is in a worn condition, loose soil from the sidewalls of a v-shaped furrow will spill into the furrow before the seed or seed and fertilizer are deposited. Alternatively, if the seed boot is in a worn condition, the seed and the fertilizer may be blown or bounced around or out of the furrow altogether such that the seed and fertilizer are prevented from being deposited in the furrow or from reaching a proper planting depth. To compensate for a worn seed boot in order to achieve proper seed planting depth and to prevent soil from collapsing in the v-shaped furrow prior to depositing of the seed and fertilizer, the worn seed boot must either be continually adjusted for proper height with the bottom of the furrow or the seed boot must be replaced. Replacement of a worn seed boot results in loss of planting time and reduced cost efficiency. Therefore, it will be appreciated that increasing the life of the parts of a seed planter shall also increase efficiencies in seed placement, crop yields, planting time and also decrease overall maintenance of the planters. Previous attempts to improve the wear life of the seed boot have met with limited success. For example, it was found that the heat treatment and quenching process of the manufacture of a seed boot resulted in cracks forming during the quenching process, thereby rendering the seed boot unacceptable. Furthermore, overlays of tungsten carbide materials in a base matrix resulted in a rough surface and protrusions such that soil material would build up on the seed boot. This caused poor seed bed quality and compromised seed and fertilizer separation.
Those skilled in the art shall appreciate that austempered ductile iron or chrome iron castings have been and are currently employed for the manufacture of a paired row and sideband seed boots. While these double shoot and single shoot seed boot castings allow for the separate placement of seed and fertilizer in one, pass, they each have drawbacks. Chrome iron castings are used for wearability but lack toughness. Austempered ductile iron castings are used for toughness but lack wearability. Carbide inserts have been employed and were successful in maintaining the shape of the furrows, but are very brittle and thus unacceptable.
U.S. Pat. No. 5,743,033 (Gegel) discloses a ground engaging tool for an earth working machine. Gegel discloses a ground engaging element comprising a metal base component and a metal matrix composite component wherein the metal matrix composite component is bonded to the metal base component. Gegel discloses that the metal matrix composite component is cast in place. The metal matrix composite component consists of a preform having inter-connecting porosity. The preform is formed from a material selected from a ceramic, a cermet or mixtures thereof The preform is infiltrated by the infiltration metal and the infiltration metal is fusion bonded to the metal based component. Gegel is unconcerned and does not disclose the special dual carbide inserts of the present invention that are brazed to an austempered ductile iron casting. Gegel does not teach or suggest the dual carbide inserts of the present invention having a higher concentration of cobalt contained in the leading insert and a lower concentration of cobalt contained in the trailing insert.
U.S. Pat. No. 5,697,308 (Rowlett) discloses a seed boot for use with a furrow forming disc of a grain drill for depositing seed within a furrow. The seed boot has at least one side wear insert attached to the lower edge of the outer side of the seed boot to prevent side and down force wear of the seed boot. Rowlett teaches that the side wear inserts are comprised of a cemented tungsten carbide containing cobalt as a binder.
U.S. Pat. No. 6,318,279 (Rowlett et al.) discloses a seed boot attachment wherein a wear resistant insert is secured to at least one of the exterior leading surfaces of a furrow forming point of a seed boot. Rowlett et al. is unconcerned with and does not teach or suggest the use of dual carbide wear resistant inserts of the present invention.
U.S. Pat. No. 6,332,412B1 (Swab, et al.) discloses a ground engaging paired row furrow forming tool. Swab, et al. discloses a tool body having fore and aft ends, an outer edge on each of two opposing sides of the tool body, and a furrowing wing adjacent to each of the opposing sides of the tool body and protruding from the bottom portions of the tool body. Swab, et al. discloses that each wing includes an outer surface that extends downwards and inwards from the outer edge and a fore surface that extends from the central front portion of the lower surface of the tool body downwards and outwards to intersect with the outer surface of the wing at a furrowing edge portion of the wing. Swab et al. is unconcerned and does not disclose the dual carbide inserts of the present invention.
It will be appreciated that the earth working machinery industry has been designing ground engaging tools that have a combination of abrasion-resistance and impact-resistance over the years. Those skilled in the art understand that high wear resistance is achieved by increased hardness of a component while high impact strength is attained by increasing the fracture toughness of the component. Those skilled in the art in the industry are aware that the useful life of a cutting edge of a ground engaging component may be increased if it has a combination of both wear and impact resistance. In spite of this background art, however, there remains a very real and substantial need for an improved seed boot as provided by the instant invention to enhance wear life of the seed boot while maintaining the proper seed planting depths and the critical separation between the seed and the fertilizer, and the smooth flow of the seed boot through the soil.
The present invention provides a planting tool for depositing a fertilizer, a seed or both within a furrow. The planting tool comprises a soil opener and a single or paired row opener (seed boot) wherein the soil opener places fertilizer and the single or paired row opener places seed. The soil opener has a frontal lower body portion and an upper body portion and a rear portion and a rear portion. The soil opener includes a furrowing tip secured to the frontal lower body portion of the soil opener. Preferably, the planting tool includes a paired row opener (seed boot) fastened to the rear of the soil opener. The paired row seed boot includes two furrow forming wings that protrude below the body of the seed boot. The seed boot includes lower surfaces and upper surfaces, certain of which converge together to form outer edges that extend along the left and right sides of the seed boot. Each furrow forming wing has a forward lower surface, an inner surface and an outer surface. The seed boot of the present invention has at least one wear resistant leading insert secured to at least a portion of one of the forward lower surfaces of the furrow forming wings and at least one wear resistant trailing insert secured.to at least a portion of one of the forward lower surfaces of the furrow forming wings. The wear resistant leading insert is positioned in front of and in juxtaposition to the wear resistant trailing insert. Preferably, the wear resistant inserts are secured to the surfaces of the furrow forming wing by brazing.
In a preferred embodiment of this invention, the wear resistant leading insert comprises from about 15 to 22 weight percent cobalt with the remainder being tungsten carbide and wherein the wear resistant trailing insert comprises from about 8 to 14 weight percent cobalt with the remainder being tungsten carbide.
Another embodiment of this invention provides a modular seed planting system comprising an elongated tool bar supported for movement by a plurality of wheels and which is adapted to be towed in a given forward direction by a power source such as that provided by a tractor. Attached to the tool bar are a plurality of planting tools mounted along the length of the tool bar. Each planting tool includes a soil opener, and a seed boot attached to the soil opener. The seed boot comprises the seed boot of the present invention having the wear resistant inserts as described hereinabove and herein.